Tunable intrinsic spin Hall conductivity in bilayer PtTe2 by controlling the stacking mode

We report a systematic study on the intrinsic spin Hall conductivity (ISHC) of bilayer ${\mathrm{PtTe}}_{2}$ and explore the connection between the stacking order and ISHC. We find that by changing the stacking mode, ISHC can be manipulated from positive to negative values. Such strong stacking-dependent ISHC originates from the interlayer coupling, in which Te atoms in the upper and lower layers can form either van der Waals or covalentlike quasibonding depending on the stacking modes. Thus ISHC can be effectively tuned by changing the stacking order. These results not only allow us to establish fundamental understanding of ISHC in bilayer ${\mathrm{PtTe}}_{2}$ dependent on the stacking mode but also provide guidelines for the application of bilayer ${\mathrm{PtTe}}_{2}$ in next-generation spintronic devices.